Changes in Accumulated Other Comprehensive Income by Component - Summary of Changes in Accumulated Balances for Each Component of Accumulated Other Comprehensive Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning	$ (5.5)	$ 8.1	$ 10.3	$ 4.2
Other comprehensive income before reclassifications	(16.7)	(0.4)	(32.6)	3.4
Amounts reclassified from accumulated other comprehensive income	0	0.1	0.1	0.2
Balance, ending	(22.2)	7.8	(22.2)	7.8
Foreign Currency Translation [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning	(2.3)	10.9	13.6	7.6
Other comprehensive income before reclassifications	(16.7)	(0.5)	(32.6)	2.8
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Balance, ending	(19.0)	10.4	(19.0)	10.4
Available-for-Sale Securities [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning	1.9	1.6	1.9	1.1
Other comprehensive income before reclassifications	0	0.1	0	0.6
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Balance, ending	1.9	1.7	1.9	1.7
Pension and Post-Retirement Liabilities [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning	(5.1)	(4.4)	(5.2)	(4.5)
Other comprehensive income before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income	0	0.1	0.1	0.2
Balance, ending	$ (5.1)	$ (4.3)	$ (5.1)	$ (4.3)